HEF - Hi, working towards diagnosing if my main pump needs a rebuild. When purchased the guy said the pump was weak and would most likely need a rebuild. The machine appears to have 6,700 hours. So my basic testing to confirm has been to push against a tree, and the machine applies some power, and then hydraulics just seem to reach their max. No change in engine RPMs. So guessing that's a sign, as does not the engine pull back if max hydraulics are applied? I also have a manual throttle, so the electronic load balance would not throttle back the engine as OEM. Also, when taking the brake off, the pump wines pretty loud. Hydraulics are all electronic, all sensors work, no codes on the pump computer. Any other basic procedures I can test for the pump?
Good day I suggest you pull the suction filter and check for blockage, if you have a heavy grade of fluid can also make the pump whine. Kind regards Uffex
I would start with a complete service of the machine and all fluids/filters. Do you have manuals for the machine?
Has someone checked the electronics with a Dr. EX or Dr. ZX? As I recall there was little to no diagnostics on the monitor panels of those machines.
HEf - Thanks for the info. Ok reporting status as of today. Videos now uploaded 1. Hydraulic tank filter checked. Clean and looks new. (Prior owner did say full service done like 50 hours prior to me purchasing). 2. After running for about 30min, tried to push over about a 8" pine tree, she struggled to get it down. After she was slow to crawl back, then pretty much stopped in position. So guessing a pump due to getting hot? 3. Around the pilot valve area, when running, no movement of hydraulics, it makes a thrusting pulse noise. I did a video but not sure you can see here? 4. Inside the cab same type of pulsing noise can be heard, video also. 5. If I know where to buy a legit Dr. EX or Dr. Zx I would. Any more thoughts on the field test? Videos Below: Valve Area Noise: https://youtube.com/shorts/gj6Pj72fZeo Inside Cab Noise: https://youtube.com/shorts/cGnUbzKswqE
HEF new news today... 1. Whining noise that I showed in the video is coming from the foot control lever for the pilot control, as soon as brake is disengaged it starts whining. Does anyone know if that is normal? Its right next to the foot controls; it has its own foot control. 2. Still have that pulsing, maybe suction noise in the valve control area, per video. Any help is greatly appreciated.
HEF - So the foot valve control is an option for breaker and crusher attachment. Maybe I can just bypass it at the pilot valve?
No codes confirmed with a jumper? For the weak hydraulics, has pilot pressure been checked? Pilot reducing pressure? System pressure? Track cycle time? Pump displacement solenoids been swapped around to see if anything changes? You really need DrZx, Ex or whatever people use for them. Unfortunately MPDr is a dealer only software, even though there are piroted copies out there with hit or miss results on whether they work or not. I can't help with the noise, however.
@mg2361 - Thanks, Dr. EX is on the way(1 week out), and hydraulic test gauges are as well(couple of days). So will start measuring pressures. As for the noise at the foot control pilot valve, I will see if at the valve controller if I can plug all the auxiliary ports up to eliminate it.
HEF- Ok, located the whine noise to that aux pilot control and now noticed some lines capped and plugged into it. so the picture shows the rusted aux pilot to right, and then look at foot control tee going over to there and the plugged line from main valve plugged. guessing I can totally plug off the rusted aux pilot control?
Update to above. Blocked off fittings, the loud whining noise is gone. Machine sounds different and quiet Still awaiting Dr. Ex and gauge set to start checking, as seems still to not have very much power when full pressure is exerted onto something.
Have Dr. Zx, but it will not connect. Selected machine type as EX-3 or older, and then connect, attempts connect with orange connecting line, then error, says check com port is correct. I checked RS232 driver says it loaded, and Com port 4 is selected. Computer sees RS232 usb in com port 4. Prior owner said Hitachi did connect and check out machine. Does this have anything to do with me using manual throttle and my engine computer is dead? Pump controller computer is operational and blinking as normal. Any thoughts?
Having only ever using MPDr, I would not have an answer for you. All I can suggest is testing the voltages at the 4 pin connector. I believe the voltages you should see are below.
Hey thanks, will check. I actually have MpDr, guess it’s also called the Dr ZX? But when it opens it’s MPDr
All voltage is good, I think it may be related to my driver, as I have an older Win 7 laptop, but it won’t let me install the win 7 driver.
I would try searching windows 7 forums for driver installation issues. I assume your mpdr came on a disc. Are you trying to install the drivers from the disc? I tried to get drzx for a laptop and it came with a cd that was corrupted and could not be installed properly. The instructions were vague but mentioned turning off any kind of anti virus software. I did not want to do that cause when I scanned the files there appeared to be some dangerous stuff in there. I ended up doing what others had suggested and bought a palm pilot that already had drzx loaded onto it. Although recently I have been having trouble connecting. I will have to check again with that picture that mg2361 posted.
MPDr and Dr. ZX are not the same thing. You either have one or the other, regardless of what your screen says. I only ever heard of Dr. ZX on a palm pilot version, I have never seen it on a desktop version. Unfortunately, I have never used anything but MPDr, so I may be learning something here myself. Post a picture of the screen you have.
@mg2361 , and HEF, ok put manual gauge on main pump. Let it warm up, and started pulling levers. Dropped bucket in front of track and pulled back lever. Below is psi and engine never struggled or smoked just kept at full throttle. main pump psi : 3,000 Pilot psi: Dam plug is stripped…
HEF - Update, Pilot pump pressure measured: Pilot pump psi idle: 750 Pilot pump psi WOT: 850-900
Sounds like you have a low pressure issue like me. Maybe we can solve this together! Was your 3000 psi reached using "P" mode? I assume that's what you mean when you said "full throttle". You have a hand throttle though right? For pilot primary pressure the spec is 52 +10, -0 kg/cm2. That works out to a range of 740-880 psi. idle: 640 psi P mode: 690 psi I then added a 2mm thick washer to the stack of shims that were already in the pilot pressure regulator. idle: 720 psi P mode: 790 psi I decided to leave it there. Elsewhere in the manual I have seen a spec of 711 psi being called for.
Don't forget to check the Pilot Pressure Reducing Valve pressure also. That pressure is critical to the operation of the compensator valves.
@Jason Klassen and @mg2361 , @LACHAU ?? Yes all tests where in P mode. I am not sure where the pilot pressure reducing valve location is to test. Any diagrams? So these tests don’t lend to a main pump needing a rebuild? I thought pump pressure was to be at 4200psi?
In the Hitachi manual, it would be listed as the Pilot Secondary Pressure (section 6, group 4). You do have the Technical manual, correct? Low pump pressure does not necessarily mean a bad pump. That machine has too many variables that could cause poor performance. The only way to be sure about the pump is to perform a pump flow test.
@mg2361 - Thanks. I see in the tech manual you need a fitting and T, I only have hydraulic gauges and the fitting, so will need to find a T. How may I do a pump flow test?
Also, that pilot second pressure t’s back into the 4th line on that block. That’s different than from the tech manual.
That takes special equipment that cost $$$$. You would need someone who already has that tooling and the knowledge of how to flow test that pump on that system. Check your PM's.
What do you have running off that last spool? That one on the end on the left side is the auxiliary. On mine I have a thumb and the line for the compensator just returns to the top of the spools where the pilot lines are and then to the tank. So my compensator for the thumb is never used. Yours looks like its teed into the bucket compensator so that the bucket and the thumb (if that's what you have) receive the same compensation. @mg2361 , would this setup be beneficial compared to mine?
Off the top of my head, I don't know. I would have to study this.
@mg2361 , ok secondary pilot test done. 0 psi on below port. Unless I did something wrong. Full throttle, same bucket push against tracks, nothing. picture below of port I tested with gauge. what’s that mean?
Looks to me like you may have been trying to measure PC Pressure and not pilot secondary pressure. I have attached some pics from the manual. Its a little confusing because in 4.2 Pilot Secondary Pressure the darkened line in the first pictures is the one you were testing (goes to a compensator) and the second picture shows the gauge connected to a pilot line at the top of the main control valve.
Actually the Pilot Secondary pressure can be checked at the solenoid manifold. Check your PM.